Following the difficult economic situation various countries introduced health sector reforms, including user charges to finance the system. The assessment of user costs for maternity services in Tanzania was part of a larger study, which covered inputs, outputs and efficiency of services. The study was carried out from October 1997 to January 1998 in Mtwara urban and rural district in South Tanzania. One hundred and seven women attending a quarter of government health facilities were randomly selected and interviewed. Twenty one key informants were also interviewed and service procedures observed. Users of maternity services pay mainly for admission, drugs, other supplies and travel costs. Travel costs represent about half of these financial costs. The average total costs vary between US$11.60 for antenatal consultation and US$135.40 for caesarean section at the hospital. Unofficial payments are not included in the calculation. The amounts vary and payment is irregular. We therefore conclude that time costs are constantly higher than financial costs. High direct payments and the fear of unofficial costs are acute barriers to the use of maternity services. User costs can substantially be reduced by the re-organisation of service delivery especially at antenatal consultation.